The aim of this project is to study the transcriptional regulation of myocardial hypertrophy. Using the acute pressure overload model of left ventricular hypertrophy we will study RNA polymerase and chromatin template activity in separated cardiac muscle and non-muscle cells. Various RNA polymerases will be solubilized, fractionated and characterized from hypertrophying cardiac tissue. Acidic non-histone (NHP) and histone proteins will be extracted from chromatin and separated on SDS polyacrylamide gels. We will also study the effects of reconstituting chromatin with various NHP fractions on RNA synthesis. The specificity of the binding of these proteins to DNA as well as the role of phosphorylation will be examined.